Composite structures are used in a wide variety of applications. In aircraft construction, composites are used in increasing quantities to form the fuselage, wings, tail section, and other components. For example, the wings may be constructed of composite skin members to which stiffening elements, such as stringers, may be coupled to increase the bending strength and stiffness of the skin member. The stringers may extend in a generally span wise direction along the wing, i.e., approximately from the wing root to approximately the wing tip. The stringers may be bonded to the skin members.
The stringers in a wing may extend from an inboard section of the wing to an outboard section of the wing. The stringers may include purely structural stringers and also stringers that serve both a structural and a systemic purpose, such as vent stringers. Vent stringers may act as a conduit for venting fuel and fuel vapors from the inboard section of the wing fuel tanks to the surge tanks farther out in the wings. The vent stringers may carry fuel or fuel vapors during refueling or during flight operation of the aircraft, when pressure changes may require venting of the fuel aircraft tanks.
The manufacturing of composite components, particularly for aircraft, typically involves abrading an external surface of a partially complete composite component, so that subsequent layers, such as sealing layers, and/or other components, may form better bonds with the exterior surface. Additionally or alternatively, the external surface of a complete composite component may be abraded so that other components may form better bonds with the exterior surface. The abrading of the surface may be carried out, for instance, using a conventional sheet of sand paper. However, alternative abrading techniques and equipment can help decrease processing time and associated costs.